Embolic protection system

ABSTRACT

A retrieval catheter  1  comprises a distal tubular sheath  2  with a reception space  5  into which an embolic protection filter  10  may be retrieved. An elongate connector  10  extends proximally from the sheath  2  to allow a clinician to control movement of the sheath  12 . The sheath  2  is backloaded over a procedural catheter such as a balloon catheter  20 , for example for post dilatation of a stent  55 . The procedure is more efficient and procedure time is reduced because a catheter system is provided which allows a procedural step to be carried out and a filter  50  to be retrieved.

This is a divisional of application Ser. No. 10/436,239 filed May 13, 2003, which claims benefit of priority under 35 U.S.C. § 119(e) based on U.S. Provisional Application No. 60/379,396 filed May 13, 2002, and U.S. Provisional Application No. 60/412,545 filed Sep. 23, 2002. The entire disclosures of the prior applications, application Ser. Nos. 10/436,239, 60/379,396 and 60/412,545 are hereby incorporated by reference.

BACKGROUND OF THE INVENTION

This invention relates to a system for carrying out an interventional procedure in the vasculature.

During an interventional procedure, it is known to deploy an embolic protection filter distally of a treatment site in a vasculature using a delivery catheter. The filter is used to capture any embolic material generated during a treatment procedure subsequently performed at the treatment site. After completion of the treatment procedure the filter and the captured embolic material are retrieved from the vasculature using a retrieval catheter.

This invention is aimed at providing a system which enables an interventional procedure of this type to be carried out more efficiently.

SUMMARY OF THE INVENTION

According to the invention there is provided a method for carrying out an interventional procedure at a treatment location in a vasculature comprising the steps of:

-   -   deploying an embolic protection device distal of a treatment         location in a vasculature;     -   providing a procedural catheter for carrying out a procedure at         a treatment site in the vasculature, the procedural catheter         having a proximal end and a distal end;     -   providing an embolic protection device retrieval catheter having         a distal end defining a reception space for an embolic         protection device and a proximal end;     -   loading the proximal end of the retrieval catheter over the         distal end of the procedural catheter;     -   advancing the procedural catheter to the treatment location;     -   advancing the retrieval catheter over the procedural catheter to         present the distal end of the retrieval catheter to the deployed         embolic protection device;     -   retrieving the embolic protection device into the retrieval         catheter; and     -   removing the retrieval catheter and with it the embolic         protection device from the vasculature.

In one embodiment the procedural catheter is a balloon catheter and the method comprises carrying out a procedure by inflating the balloon at the treatment location. In one arrangement, on inflation of the balloon, the retrieval catheter is located proximal of the balloon.

The invention also provides deflating the balloon and advancing the retrieval catheter over the deflated balloon.

In another embodiment the procedural catheter is an angioplasty catheter and the method comprises carrying out an angioplasty procedure at the treatment location.

In a further embodiment the procedural catheter is a stent deployment catheter and the method comprises deploying a stent at the treatment location. The stent may be a balloon expandable stent and the method comprises inflating the balloon to deploy the stent.

In another embodiment the procedural catheter is a post dilatation catheter, and the method comprises carrying out a post dilatation procedure at the treatment location.

The embolic protection device may be engaged with the distal end of the retrieval catheter for retrieval of the embolic protection device.

In another aspect the method comprises:

-   -   providing a retrieval snare;     -   engaging the embolic protection device with the snare; and     -   retrieving the snared embolic protection device into the         retrieval catheter.

In one embodiment the embolic protection device comprises an embolic protection filter which is expandable from a collapsed delivery configuration to an expanded deployed configuration for capturing embolic released during an interventional procedure.

The retrieval catheter may have a radiopaque marker adjacent the distal end thereof and the method comprises positioning the retrieval catheter for retrieval of the filter by visualization of the radiopaque marker.

In one embodiment the retrieval catheter has an expansible distal portion for receiving the captured embolic protection device.

The invention also provides an interventional catheter system comprising:

-   -   a procedural catheter for carrying out a procedure at a         treatment site in the vasculature, the procedural catheter         having a distal end and a proximal end; and     -   an embolic protection device retrieval catheter having a distal         end defining a reception space for an embolic protection device         and a proximal end, the proximal end of the retrieval catheter         being adapted for loading over the procedural catheter.

In one embodiment the proximal end of the retrieval catheter is adapted for loading over the distal end of the procedural catheter.

The retrieval catheter may comprise a distal tubular portion defining the reception space for a retrieved embolic protection device and a control element to control movement of the tubular portion. The tubular portion is preferably shorter than the length of the procedural catheter. The distal tubular portion may have a length of less than 35 cm.

In one embodiment the control element comprises an elongate connector extending proximally of the tubular portion. The connector may comprise a wire.

In one embodiment the connector is fixed to the tubular portion.

The connector may be integral with the outer tubular body.

In one embodiment the tubular portion is expandable.

In one arrangement the tubular portion comprises a coiled sheath, the sheath being expandable by uncoiling.

The tubular portion may comprise one or more reinforcement columns. In one version the ratio of the cross-sectional area of the column to the cross-sectional area of the tubular portion is substantially constant along the length of the tubular portion. In another version the ratio of the cross-sectional area of the column to the cross-sectional area of the tubular portion decreases distally along at least part of the length of the tubular portion. The column may comprise a spline.

In one embodiment the tubular portion comprises a radiopaque marker. The radiopaque marker may comprise a band that extends at least partially around the tubular portion.

The radiopaque marker may be generally C-shaped.

The connector may form an extension of the radiopaque marker.

In one embodiment the system comprises an engagement element for engaging with an embolic protection device for retrieval of the device into the retrieval catheter. The engagement element may comprise a snare.

In one embodiment the procedural catheter is a balloon catheter.

In another embodiment the procedural catheter is an angioplasty catheter.

In a further embodiment the procedural catheter is a post dilatation catheter.

In one version the procedural catheter is a stent deployment catheter.

In another version the procedural catheter is a balloon expandable stent deployment catheter.

The catheter system may comprise a delivery catheter.

The catheter system in one embodiment comprises an embolic protection device.

In another aspect the invention provides a catheter having a reception space for receiving a medical device, the catheter being expandable around the reception space for ease of movement of a medical device relative to the reception space.

In this aspect the catheter may comprise a coiled sheath around the reception space, the sheath being expandable by uncoiling.

In a further aspect the invention provides a transportation device comprising a reception portion having a reception space for receiving a medical device, and a control tether extending proximally of the reception portion to facilitate control of the position of the reception portion. The reception portion may comprise a tubular sheath.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be more clearly understood from the following description of some embodiments thereof, given by way of example only, with reference to the accompanying drawings, in which:

FIG. 1 is a perspective view of a retrieval catheter according to the invention;

FIG. 2 is a perspective view of a treatment catheter used in the invention;

FIG. 3 is a perspective view illustrating the assembly of the catheter of FIG. 1 to the catheter of FIG. 2;

FIG. 4 is a perspective view of a catheter system of the invention comprising the retrieval catheter of FIG. 1 and the treatment catheter of FIG. 2;

FIGS. 5(A) to 5(F) are diagrammatic side partially cross-sectional views of the catheter system of FIG. 4, in use;

FIG. 6 is a side, partially cross-sectional view illustrating an alternative arrangement using the catheter system of FIG. 4;

FIG. 7 is a perspective view of another catheter system of the invention;

FIG. 8 is a perspective view of a further catheter system of the invention;

FIG. 9 is a perspective view of a retrieval catheter of the invention;

FIG. 10 is a perspective view of another retrieval catheter of the invention;

FIG. 11 is a perspective view of a further retrieval catheter of the invention;

FIG. 12 is a perspective view of another retrieval catheter of the invention;

FIG. 13 is a perspective view of a further retrieval catheter of the invention;

FIGS. 14(A) and 14(B) are perspective views of a catheter system illustrating the retrieval catheter of FIG. 13, in use;

FIG. 15 is a perspective view of another retrieval catheter of the invention;

FIG. 16 is a cross-sectional view of the line A-A in FIG. 15 in one configuration of use;

FIG. 17 is a cross-sectional view on the line A-A of FIG. 15 in another configuration of use;

FIG. 18 is a perspective view of another retrieval catheter system of the invention;

FIGS. 19(A) to 19(C) are perspective views of the catheter system of FIG. 18, in use;

FIG. 20 is a perspective view of another retrieval catheter of the invention;

FIG. 21 is a perspective view of a further retrieval catheter of the invention;

FIGS. 22(A) and 22(B) are perspective views of the catheter of FIG. 21, in use; and

FIG. 23 is a side, partially cross-sectional view of another catheter system of the invention operating in a rapid exchange mode.

DETAILED DESCRIPTION OF THE INVENTION

Referring to the drawings there are illustrated various catheter systems according to the invention. The catheter system comprises a retrieval catheter having an internal reception space for receiving an embolic protection filter to enable the filter to be transported through a vasculature, and a treatment/procedural catheter to facilitate carrying out a procedure or treatment at a site in the vasculature such as a region of stenosis.

The retrieval catheter according to the invention which may be used to retrieve from a vasculature an embolic protection filter, such as an embolic protection filter as described in International patent applications Nos. PCT/IE00/00053 (U.S. Ser. No. 09/985,820, U.S. Patent Publication No. U.S. 2002-0107541 A1), and/or PCT/IE00/00054 (U.S. Ser. No. 09/986,132, U.S. Patent Publication No. 2002-0058911 A1 (now abandoned)), and/or PCT/IE00/00055 (U.S. Ser. No. 09/986,064, U.S. Pat. No. 6,726,701, issued Apr. 27, 2004), and/or PCT/IE98/00093 (U.S. Ser. No. 09/188,472, U.S. Pat. No. 6,336,934, issued Jan. 8, 2002), the relevant contents of which are incorporated herein by reference.

In use, an embolic protection filter 50 is collapsed down and loaded into a reception space of a delivery catheter, for example, in a manner similar to that described in International patent application No. PCT/IE01/00052 (U.S. Ser. No. 09/838,544, U.S. Pat. No. 6,887,256, issued May 3, 2005), the relevant contents of which are incorporated herein by reference. The delivery catheter is then introduced into a vasculature and advanced through the vasculature to cross a desired treatment site in the vasculature. The filter is deployed out of the delivery catheter at a deployment site distally of the treatment site, and the delivery catheter is withdrawn from the vasculature.

A catheter system of the invention is assembled by backloading a retrieval catheter over a procedural/treatment catheter as will be described in more detail below.

A catheter system of the invention is then introduced into the vasculature, and advanced through the vasculature over a guidewire in the introduction configuration.

When the procedural catheter is located at the treatment site a procedure is carried out at the site using the procedural catheter. Any embolic material generated during the treatment procedure is captured by the deployed filter 50.

After completion of the treatment procedure, and the retrieval catheter is advanced over the procedural catheter until the distal end is immediately proximal of the deployed filter. The filter is then retrieved into the retrieval catheter, for example, in a manner similar to that described in International patent application No. PCT/IE01/00053 (U.S. Ser. No. 09/838,545, U.S. Patent Publication No. US 2002-0049467 A1 (now abandoned)), the relevant contents of which are incorporated herein by reference. Any embolic material captured by the filter 50 is safely retained within the filter 10 during this retrieval step.

The catheter system and the retrieved filter 50 are then withdrawn from the vasculature. In this way any embolic material retrieved during the interventional procedure is safely captured and removed from the vasculature.

Referring to FIG. 1 there is illustrated a retrieval catheter 1 which comprises a tubular portion 2 or sheath having a proximal end 3 and a distal end 4. The tubular portion 2 defines a reception space 5 at the distal end thereof into which an embolic protection device may be at least partially retrieved. An elongate connector 10, in this case in the form of a wire; is provided fixed to the tubular portion 2 and extends proximally therefrom. The connector wire 10 provides a clinician using the catheter 1 with a control element to control movement of the tubular portion 2, in use. The catheter 1 may be used in an over-the-wire as illustrated in FIG. 5(B) or a rapid exchange mode as illustrated in FIG. 23. In general, the tubular portion 2 has a length of less than 35 cm. The length must be such as to ensure that the proximal end of the retrieval catheter is proximal of a stent during filter retrieval. The length must also be such as to ensure that the retrieved filter can be housed in the retrieval catheter.

A catheter system of the invention comprises a retrieval catheter 1 and a procedural/treatment catheter 20 which is illustrated in FIG. 2. The procedural catheter 20 is in this case a balloon catheter having a proximal end 21 fitted with a Y connector 22 to provide an external inflation port for inflating a balloon 23 adjacent to a distal end 24 of the catheter 20. Such balloon catheters are well known in the art and this invention can be applied generally to any suitable procedural/treatment catheter.

As illustrated in FIGS. 3 and 4, a catheter system 30 of the invention is assembled by backloading the retrieval catheter 1 onto the procedural catheter 20. The proximal end 3 of the retrieval catheter tubular portion 2 is presented to the distal end 24 of the procedural catheter 20 and slid proximally therealong as illustrated in FIG. 3 until the distal end 4 of the tubular portion 2 is proximal of the procedural/treatment element of the catheter 20, in this case proximal of the balloon 23.

In use, the catheter system 30 is loaded over a guidewire 40 which extends proximally from the vasculature through a guide catheter 45 fitted with a proximal Touhy Borst 46 having a Y connector and a haemostatis valve [FIG. 5(A)]. An embolic protection filter 50 is deployed in a vasculature 51 distal of a treatment location, in this case a region of stenosis 52. In this case the region of stenosis 52 has been treated using, for example an angioplasty balloon followed by a stenting, using for example a self expanding stent 55. One such stent is described in U.S. Pat. No. 5,827,321.

The catheter system 30 of the invention is used for the final stages of a procedure. The procedural catheter 20 is advanced [FIG. 5(B)] along the guidewire 40 until the balloon 23 is located at the deployed stent 55 at the lesion site. The balloon 23 is then inflated [FIG. 5(C)] in a post-dilatation procedure to expand the stent 55 further to ensure engagement in position. The balloon 23 is then deflated [FIG. 5(D)] and the retrieval catheter tubular portion 2 is advanced over the procedural catheter using the control wire 40 until the distal end 4 of the tubular portion 2 is adjacent the proximal end of the filter 50. The filter 50 is then at least partially retrieved into the reception space 5 [FIG. 5(E)] in the tubular portion 2. The catheter system comprising the retrieval catheter 1 containing the retrieved embolic filter 50 is then withdrawn over the guidewire 40 [FIG. 5(F)] and removed from the vasculature. Alternatively the procedural catheter 10 may be withdrawn from the vasculature first followed by the retrieval catheter 1 and retrieved filter.

The catheter systems of the invention offer substantial advantages in facilitating a quicker and more efficient procedure. In the case where the procedural catheter is a balloon catheter, the balloon may be used to assist in crossing a stent with the retrieval catheter. In general, the use of a procedural catheter provides a more substantial track (than a guidewire) for a retrieval catheter.

In the procedure described above the tubular portion 2 of the retrieval catheter 1 is maintained just proximal of the balloon 23 during the treatment procedure. However, the tubular retrieval portion 3 may be located at any suitable position and indeed external of the Touhy Borst 46 as illustrated in FIG. 6 until retrieval is required.

It will be appreciated that the procedural catheter may be used for carrying out any desired procedure. For example, in the catheter system 60 of FIG. 7 the procedure may be deployment of a stent such as a balloon expandable stent 61. Indeed, the procedural catheter 62 may be for lysis or diagnostic/visualization in other catheter systems 63 of the invention.

The retrieval catheter 1 is particularly suitable for rapid exchange over a guidewire. Because the connector wire 10 has a very low profile, relative movement between the wire 10 and the procedural catheter 20 will not interfere with passage of a guidewire through a rapid exchange port in the procedural catheter 20.

As illustrated in FIG. 9, the connector wire 10 may alternatively be provided integral with the tubular portion 2. The wire 10 extends along the length of a soft, expandable outer tubular portion 2 to impart column strength to the tubular portion 2.

In the retrieval catheter 70 of FIG. 10, the tubular portion 71 comprises two reinforcement columns 72 extending along the length of the tubular portion 71 separated by two portions 73 of soft, expandable material. In FIG. 10, the ratio of the cross-sectional area of the columns 72 to the cross-sectional area of the soft portions 73 remains constant along the length of the tubular portion 71.

The columns 72 provide column strength to the soft portions 73 to minimize the possibility of buckling of the tubular portion 71 during retrieval of an embolic protection filter into the reception space 5.

Another retrieval catheter 80 is illustrated in FIG. 11. In this a tubular portion 81 comprises four reinforcement columns 82 extending along the length of the tubular portion 81 separated by four portions 83 of soft, expandable material. The columns 82 are in the form of distally tapering splines, such that the ratio of the cross-sectional area of the columns 82 to the cross-sectional area of the soft portions 83 decreases distally along the length of the tubular portion 81.

In the retrieval catheter 90 of FIG. 12 a tubular portion 91 comprises a distal portion 92 of soft, expandable material mounted to a rigid proximal portion 93. The connector wire 10 is fixed to the rigid proximal portion 93.

Referring to FIG. 13 there is illustrated another retrieval catheter 100 with a distally tapered soft distal tip 101 and a relatively harder main tubular portion 102. To facilitate visualization in use the tubular portion has a radiopaque marker band 103. A catheter system comprising the retrieval catheter 100 and any suitable procedural catheter 20 is shown in FIGS. 14(A) and 14(B).

Referring now to FIG. 15 there is illustrated another retrieval catheter 110 which is similar to the catheter of FIG. 13 except that in this case there is a C-shaped marker band 111. This arrangement of marker band does not restrict radial expansion of the tubular portion/pod 102 as will be apparent from FIGS. 16 and 17. This expansion may be desirable to accommodate a retrieved embolic protection device.

Referring to FIG. 18 there is illustrated another retrieval catheter system 120. The tubular portion 91 is similar to that described with reference to FIG. 12. The system in this case includes a snare to facilitate retrieval of the filter 50 into the reception space 5. The snare comprises a snaring hoop or loop 121 and a control wire or tether 121 extending proximally. In use, as illustrated in FIGS. 19(A) to 19(C) the tether hoop 121 is used to engage the proximal end of the filter 50 [FIG. 19(A)]. On pulling of the control wire/tether 122 the filter is pulled into the reception space 5 [FIG. 19(B)] until the filter is contained [FIG. 19(C)]. The retrieval catheter is then withdrawn from the vasculature. The connector 10 is in this case a hypotube to provide a pathway for the snare control wire/tether 122.

In FIG. 20 there is illustrated another retrieval catheter 130. In this case the connector 131 has guide hoops 132 to control movement of portion of the retrieval catheter to tie its operation to the procedural catheter.

Referring to FIGS. 21 and 22 there is illustrated another retrieval catheter 200 having a tubular portion 201 comprising a coiled sheath 202 fixed to the connector wire 10. The sheath 201 is expandable by partially uncoiling, as illustrated in FIG. 22(B), to facilitate ease of retrieval of the embolic protection filter 50 into the reception space 5.

During advancement of tubular portion 201 through a vasculature, the sheath 202 is tightly coiled down, as illustrated in FIG. 22(A). In this way, the sheath 202 presents a low-profile, introduction configuration.

During retrieval of the embolic protection filter 50 into the reception space 5, the sheath 202 is partially uncoiled by the retracting filter to maximize the internal volume of the reception space 5 for ease of retrieval of the embolic protection filter 50 into the reception space [FIG. 22(B)].

Marker bands may be placed at appropriate locations to allow the clinician to accurately carry out each step of the procedure.

These designs can be applied to push/pull or thumb screw systems. They can be used in either rapid exchange or over the wire format.

The invention is not limited to the embodiments hereinbefore described, with reference to the accompanying drawings, which may be varied in construction and detail. 

1. An interventional catheter system comprising: a procedural catheter for carrying out a procedure at a treatment site in the vasculature, the procedural catheter having a distal end and a proximal end; and an embolic protection device retrieval catheter having a distal end defining a reception space for an embolic protection device and a proximal end, the proximal end of the retrieval catheter being adapted for loading over the procedural catheter.
 2. A catheter system as claimed in claim 1, wherein the proximal end of the retrieval catheter is adapted for loading over the distal end of the procedural catheter.
 3. A catheter system as claimed in claim 1, wherein the retrieval catheter comprises a distal tubular portion defining the reception space for a retrieved embolic protection device and a control element to control movement of the tubular portion.
 4. A catheter system as claimed in claim 3, wherein the tubular portion is shorter than the length of the procedural catheter.
 5. A catheter system as claimed in claim 3, wherein the distal tubular portion has a length of less than 35 cm.
 6. A catheter system as claimed in claim 3, wherein the control element comprises an elongate connector extending proximally of the tubular portion.
 7. A catheter system as claimed in claim 6, wherein the connector comprises a wire.
 8. A catheter system as claimed in claim 6, wherein the connector is fixed to the tubular portion.
 9. A catheter system as claimed in 6, wherein the connector is integral with the outer tubular body.
 10. A catheter system as claimed in claim 3, wherein the tubular portion is expandable.
 11. A catheter system as claimed in claim 10, wherein the tubular portion comprises a coiled sheath, the sheath being expandable by uncoiling.
 12. A catheter system as claimed in claim 3, wherein the tubular portion comprises one or more reinforcement columns.
 13. A catheter system as claimed in claim 12, wherein the ratio of the cross-sectional area of the column to the cross-sectional area of the tubular portion is substantially constant along the length of the tubular portion.
 14. A catheter system as claimed in claim 12, wherein the ratio of the cross-sectional area of the column to the cross-sectional area of the tubular portion decreases distally along at least part of the length of the tubular portion.
 15. A catheter system as claimed in claim 14, wherein the column comprises a spline.
 16. A catheter system as claimed in claim 3, wherein the tubular portion comprises a radiopaque marker.
 17. A catheter system as claimed in claim 16, wherein the radiopaque marker comprises a band that extends at least partially around the tubular portion.
 18. A catheter system as claimed in claim 16, wherein the radiopaque marker is generally C-shaped.
 19. A catheter system as claimed in claim 16, wherein the connector forms an extension of the radiopaque marker.
 20. A catheter system as claimed in claim 3, wherein the system comprises an engagement element for engaging with an embolic protection device for retrieval of the device into the retrieval catheter.
 21. A catheter system as claims in claim 20, wherein the engagement element comprises a snare.
 22. A catheter system as claimed in claim 1, wherein the procedural catheter is a balloon catheter.
 23. A catheter system as claimed in claim 1, wherein the procedural catheter is an angioplasty catheter.
 24. A catheter system as claimed in claim 1, wherein the procedural catheter is a post dilatation catheter.
 25. A catheter system as claimed in claim 1, wherein the procedural catheter is a stent deployment catheter.
 26. A catheter system as claimed in claim 1, wherein the procedural catheter is a balloon expandable stent deployment catheter.
 27. A catheter system as claimed in claim 1, comprising a delivery catheter.
 28. A catheter system as claimed in claim 1, comprising an embolic protection device.
 29. A catheter having a reception space for receiving a medical device, the catheter being expandable around the reception space for ease of movement of a medical device relative to the reception space.
 30. A catheter as claimed in claim 29, wherein the catheter comprises a coiled sheath around the reception space, the sheath being expandable by uncoiling.
 31. A transportation device comprising a reception portion having a reception space for receiving a medical device, and a control tether extending proximally of the reception portion to facilitate control of the position of the reception portion.
 32. A device as claimed in claim 31, wherein the reception portion comprises a tubular sheath. 